def report_status(scheduled_time, estimated_time):
    ''' (number, number) -> str

    Return the flight status (on time, early, delayed)
    for a flight that was scheduled to arrive at
    scheduled_time, but is now estimated to arrrive
    at estimated_time.

    Pre-condition: 0.0 <=scheduled_time <24 and
    0.0 <= estimated_time < 24

    >>> report_status(14.3, 14.3)
    'on time'
    >>> report_status(12.5, 11.5)
    'early'
    >>> report_status(9.0, 9.5)
    'delayed'
    '''

    if scheduled_time == estimated_time:
        return 'on time'
    elif scheduled_time > estimated_time:
        return 'early'
    else:
        return 'delayed'